Kernel now supports chained power-off handlers. Use
register_power_off_handler() that registers power-off handlers and
do_kernel_power_off() that invokes chained power-off handlers. Legacy
pm_power_off() will be removed once all drivers will be converted to
the new sys-off API.
Normally arch code should adopt only the do_kernel_power_off() at first,
but m68k is a special case because it uses pm_power_off() "inside out",
i.e. pm_power_off() invokes machine_power_off() [in fact it does nothing],
while it's machine_power_off() that should invoke the pm_power_off(), and
thus, we can't convert platforms to the new API separately. There are only
two platforms changed here, so it's not a big deal.
Acked-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Michał Mirosław <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
---
arch/m68k/emu/natfeat.c | 3 ++-
arch/m68k/include/asm/machdep.h | 1 -
arch/m68k/kernel/process.c | 5 ++---
arch/m68k/kernel/setup_mm.c | 1 -
arch/m68k/kernel/setup_no.c | 1 -
arch/m68k/mac/config.c | 4 +++-
6 files changed, 7 insertions(+), 8 deletions(-)
diff --git a/arch/m68k/emu/natfeat.c b/arch/m68k/emu/natfeat.c
index 71b78ecee75c..b19dc00026d9 100644
--- a/arch/m68k/emu/natfeat.c
+++ b/arch/m68k/emu/natfeat.c
@@ -15,6 +15,7 @@
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/reboot.h>
#include <linux/io.h>
#include <asm/machdep.h>
#include <asm/natfeat.h>
@@ -90,5 +91,5 @@ void __init nf_init(void)
pr_info("NatFeats found (%s, %lu.%lu)\n", buf, version >> 16,
version & 0xffff);
- mach_power_off = nf_poweroff;
+ register_platform_power_off(nf_poweroff);
}
diff --git a/arch/m68k/include/asm/machdep.h b/arch/m68k/include/asm/machdep.h
index 8fd80ef1b77e..8d8c3ee2069f 100644
--- a/arch/m68k/include/asm/machdep.h
+++ b/arch/m68k/include/asm/machdep.h
@@ -24,7 +24,6 @@ extern int (*mach_get_rtc_pll)(struct rtc_pll_info *);
extern int (*mach_set_rtc_pll)(struct rtc_pll_info *);
extern void (*mach_reset)( void );
extern void (*mach_halt)( void );
-extern void (*mach_power_off)( void );
extern unsigned long (*mach_hd_init) (unsigned long, unsigned long);
extern void (*mach_hd_setup)(char *, int *);
extern void (*mach_heartbeat) (int);
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index 221feb0269f1..2cb4a61bcfac 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -67,12 +67,11 @@ void machine_halt(void)
void machine_power_off(void)
{
- if (mach_power_off)
- mach_power_off();
+ do_kernel_power_off();
for (;;);
}
-void (*pm_power_off)(void) = machine_power_off;
+void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
void show_regs(struct pt_regs * regs)
diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
index 78ab562beb31..42691abcd908 100644
--- a/arch/m68k/kernel/setup_mm.c
+++ b/arch/m68k/kernel/setup_mm.c
@@ -98,7 +98,6 @@ EXPORT_SYMBOL(mach_get_rtc_pll);
EXPORT_SYMBOL(mach_set_rtc_pll);
void (*mach_reset)( void );
void (*mach_halt)( void );
-void (*mach_power_off)( void );
#ifdef CONFIG_HEARTBEAT
void (*mach_heartbeat) (int);
EXPORT_SYMBOL(mach_heartbeat);
diff --git a/arch/m68k/kernel/setup_no.c b/arch/m68k/kernel/setup_no.c
index 5e4104f07a44..00bf82258233 100644
--- a/arch/m68k/kernel/setup_no.c
+++ b/arch/m68k/kernel/setup_no.c
@@ -55,7 +55,6 @@ int (*mach_hwclk) (int, struct rtc_time*);
/* machine dependent reboot functions */
void (*mach_reset)(void);
void (*mach_halt)(void);
-void (*mach_power_off)(void);
#ifdef CONFIG_M68000
#if defined(CONFIG_M68328)
diff --git a/arch/m68k/mac/config.c b/arch/m68k/mac/config.c
index 65d124ec80bb..382f656c29ea 100644
--- a/arch/m68k/mac/config.c
+++ b/arch/m68k/mac/config.c
@@ -12,6 +12,7 @@
#include <linux/errno.h>
#include <linux/module.h>
+#include <linux/reboot.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/tty.h>
@@ -140,7 +141,6 @@ void __init config_mac(void)
mach_hwclk = mac_hwclk;
mach_reset = mac_reset;
mach_halt = mac_poweroff;
- mach_power_off = mac_poweroff;
#if IS_ENABLED(CONFIG_INPUT_M68K_BEEP)
mach_beep = mac_mksound;
#endif
@@ -160,6 +160,8 @@ void __init config_mac(void)
if (macintosh_config->ident == MAC_MODEL_IICI)
mach_l2_flush = via_l2_flush;
+
+ register_platform_power_off(mac_poweroff);
}
--
2.35.1
Hi Dmitry,
On Tue, May 10, 2022 at 1:34 AM Dmitry Osipenko
<[email protected]> wrote:
> Kernel now supports chained power-off handlers. Use
> register_power_off_handler() that registers power-off handlers and
> do_kernel_power_off() that invokes chained power-off handlers. Legacy
> pm_power_off() will be removed once all drivers will be converted to
> the new sys-off API.
>
> Normally arch code should adopt only the do_kernel_power_off() at first,
> but m68k is a special case because it uses pm_power_off() "inside out",
> i.e. pm_power_off() invokes machine_power_off() [in fact it does nothing],
> while it's machine_power_off() that should invoke the pm_power_off(), and
> thus, we can't convert platforms to the new API separately. There are only
> two platforms changed here, so it's not a big deal.
>
> Acked-by: Geert Uytterhoeven <[email protected]>
> Reviewed-by: Michał Mirosław <[email protected]>
> Signed-off-by: Dmitry Osipenko <[email protected]>
Thanks for your patch, which is now commit f0f7e5265b3b37b0
("m68k: Switch to new sys-off handler API") upstream.
> --- a/arch/m68k/emu/natfeat.c
> +++ b/arch/m68k/emu/natfeat.c
> @@ -15,6 +15,7 @@
> #include <linux/string.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> +#include <linux/reboot.h>
> #include <linux/io.h>
> #include <asm/machdep.h>
> #include <asm/natfeat.h>
> @@ -90,5 +91,5 @@ void __init nf_init(void)
> pr_info("NatFeats found (%s, %lu.%lu)\n", buf, version >> 16,
> version & 0xffff);
>
> - mach_power_off = nf_poweroff;
> + register_platform_power_off(nf_poweroff);
Unfortunately nothing is registered, as this is called very early
(from setup_arch(), before the memory allocator is available.
Hence register_sys_off_handler() fails with -ENOMEM, and poweroff
stops working.
Possible solutions:
- As at most one handler can be registered,
register_platform_power_off() could use a static struct sys_off_handler
instance,
- Keep mach_power_off, and call register_platform_power_off() later.
Anything else?
Thanks!
> --- a/arch/m68k/mac/config.c
> +++ b/arch/m68k/mac/config.c
> @@ -12,6 +12,7 @@
>
> #include <linux/errno.h>
> #include <linux/module.h>
> +#include <linux/reboot.h>
> #include <linux/types.h>
> #include <linux/mm.h>
> #include <linux/tty.h>
> @@ -140,7 +141,6 @@ void __init config_mac(void)
> mach_hwclk = mac_hwclk;
> mach_reset = mac_reset;
> mach_halt = mac_poweroff;
> - mach_power_off = mac_poweroff;
> #if IS_ENABLED(CONFIG_INPUT_M68K_BEEP)
> mach_beep = mac_mksound;
> #endif
> @@ -160,6 +160,8 @@ void __init config_mac(void)
>
> if (macintosh_config->ident == MAC_MODEL_IICI)
> mach_l2_flush = via_l2_flush;
> +
> + register_platform_power_off(mac_poweroff);
> }
This must have the same problem.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On 5/31/22 22:04, Geert Uytterhoeven wrote:
> Hi Dmitry,
>
> On Tue, May 10, 2022 at 1:34 AM Dmitry Osipenko
> <[email protected]> wrote:
>> Kernel now supports chained power-off handlers. Use
>> register_power_off_handler() that registers power-off handlers and
>> do_kernel_power_off() that invokes chained power-off handlers. Legacy
>> pm_power_off() will be removed once all drivers will be converted to
>> the new sys-off API.
>>
>> Normally arch code should adopt only the do_kernel_power_off() at first,
>> but m68k is a special case because it uses pm_power_off() "inside out",
>> i.e. pm_power_off() invokes machine_power_off() [in fact it does nothing],
>> while it's machine_power_off() that should invoke the pm_power_off(), and
>> thus, we can't convert platforms to the new API separately. There are only
>> two platforms changed here, so it's not a big deal.
>>
>> Acked-by: Geert Uytterhoeven <[email protected]>
>> Reviewed-by: Michał Mirosław <[email protected]>
>> Signed-off-by: Dmitry Osipenko <[email protected]>
>
> Thanks for your patch, which is now commit f0f7e5265b3b37b0
> ("m68k: Switch to new sys-off handler API") upstream.
>
>> --- a/arch/m68k/emu/natfeat.c
>> +++ b/arch/m68k/emu/natfeat.c
>> @@ -15,6 +15,7 @@
>> #include <linux/string.h>
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> +#include <linux/reboot.h>
>> #include <linux/io.h>
>> #include <asm/machdep.h>
>> #include <asm/natfeat.h>
>> @@ -90,5 +91,5 @@ void __init nf_init(void)
>> pr_info("NatFeats found (%s, %lu.%lu)\n", buf, version >> 16,
>> version & 0xffff);
>>
>> - mach_power_off = nf_poweroff;
>> + register_platform_power_off(nf_poweroff);
>
> Unfortunately nothing is registered, as this is called very early
> (from setup_arch(), before the memory allocator is available.
> Hence register_sys_off_handler() fails with -ENOMEM, and poweroff
> stops working.
>
> Possible solutions:
> - As at most one handler can be registered,
> register_platform_power_off() could use a static struct sys_off_handler
> instance,
> - Keep mach_power_off, and call register_platform_power_off() later.
>
> Anything else?
> Thanks!
>
>> --- a/arch/m68k/mac/config.c
>> +++ b/arch/m68k/mac/config.c
>> @@ -12,6 +12,7 @@
>>
>> #include <linux/errno.h>
>> #include <linux/module.h>
>> +#include <linux/reboot.h>
>> #include <linux/types.h>
>> #include <linux/mm.h>
>> #include <linux/tty.h>
>> @@ -140,7 +141,6 @@ void __init config_mac(void)
>> mach_hwclk = mac_hwclk;
>> mach_reset = mac_reset;
>> mach_halt = mac_poweroff;
>> - mach_power_off = mac_poweroff;
>> #if IS_ENABLED(CONFIG_INPUT_M68K_BEEP)
>> mach_beep = mac_mksound;
>> #endif
>> @@ -160,6 +160,8 @@ void __init config_mac(void)
>>
>> if (macintosh_config->ident == MAC_MODEL_IICI)
>> mach_l2_flush = via_l2_flush;
>> +
>> + register_platform_power_off(mac_poweroff);
>> }
>
> This must have the same problem.
The static variant should be better, IMO. I'm not sure whether other platforms won't face the same problem once they will start using register_platform_power_off(). I'll send the fix, thank you for the testing!
--- >8 ---
diff --git a/kernel/reboot.c b/kernel/reboot.c
index a091145ee710..4fea05d387dc 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -315,6 +315,37 @@ static int sys_off_notify(struct notifier_block *nb,
return handler->sys_off_cb(&data);
}
+static struct sys_off_handler platform_sys_off_handler;
+
+static struct sys_off_handler *alloc_sys_off_handler(int priority)
+{
+ struct sys_off_handler *handler;
+
+ /*
+ * Platforms like m68k can't allocate sys_off handler dynamically
+ * at the early boot time.
+ */
+ if (priority == SYS_OFF_PRIO_PLATFORM) {
+ handler = &platform_sys_off_handler;
+ if (handler->cb_data)
+ return ERR_PTR(-EBUSY);
+ } else {
+ handler = kzalloc(sizeof(*handler), GFP_KERNEL);
+ if (!handler)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return handler;
+}
+
+static void free_sys_off_handler(struct sys_off_handler *handler)
+{
+ if (handler == &platform_sys_off_handler)
+ memset(handler, 0, sizeof(*handler));
+ else
+ kfree(handler);
+}
+
/**
* register_sys_off_handler - Register sys-off handler
* @mode: Sys-off mode
@@ -345,9 +376,9 @@ register_sys_off_handler(enum sys_off_mode mode,
struct sys_off_handler *handler;
int err;
- handler = kzalloc(sizeof(*handler), GFP_KERNEL);
- if (!handler)
- return ERR_PTR(-ENOMEM);
+ handler = alloc_sys_off_handler(priority);
+ if (IS_ERR(handler))
+ return handler;
switch (mode) {
case SYS_OFF_MODE_POWER_OFF_PREPARE:
@@ -364,7 +395,7 @@ register_sys_off_handler(enum sys_off_mode mode,
break;
default:
- kfree(handler);
+ free_sys_off_handler(handler);
return ERR_PTR(-EINVAL);
}
@@ -391,7 +422,7 @@ register_sys_off_handler(enum sys_off_mode mode,
}
if (err) {
- kfree(handler);
+ free_sys_off_handler(handler);
return ERR_PTR(err);
}
@@ -422,7 +453,7 @@ void unregister_sys_off_handler(struct sys_off_handler *handler)
/* sanity check, shall never happen */
WARN_ON(err);
- kfree(handler);
+ free_sys_off_handler(handler);
}
EXPORT_SYMBOL_GPL(unregister_sys_off_handler);